Bug 1674412 - Fix intermittent rounding accuracy bug. r=gfx-reviewers,nical
Bug 1674412 - Fix intermittent rounding accuracy bug. r=gfx-reviewers,nical

Differential Revision: https://phabricator.services.mozilla.com/D117616

[ghsync] From https://hg.mozilla.org/mozilla-central/rev/2bede4bf20098addbfe570c984652c6c8d091ff0

servo/webrender,servo/webrender,servo/webrender,servo/webrender,servo/webrender,servo/webrender